System for classroom instruction in playing keyboard-type musical instruments



E. H. JOHNSON ASSROOM INSTRUCTION IN PLAYING March 8, 1960 I SYSTEM FOR CL KEYBOARD-TYPE MUSICAL. INSTRUMENTS Fil ed Jan. 11, 1957 INVENTOR. 5 d ,1 H, dofiflsan AITORA/E separateconnections between each Unitd States Patent SYSTEM FOR CLASSROOM INSTRUCTION IN PLAYING KEYBOARD-TYPE MUSICAL IN- STRUMENTS Erdman H. Johnson, Kansas City, Kans. Application January 11, 1957, Serial No. 633,598

3 Claims. (Cl. 84-470) This invention relates to the field of group instruction in the operation ofdevices such as musical instruments having a plurality of manually shiftable elements disposed in a keyboard or the like for manipulation during actual playing or operation of the device. As an illustration of the application of the invention, it will be described in terms of an exemplary embodiment especially adapted for use in instructing a group of students in the art of playing the piano. It is to be understood, however, that the invention contemplates the possible use thereof in connection with instructing groups of students in operating other musical instruments having manually shiftable elements, such as the organ or even various wind instruments, as well as in the operation of such devices as typewriters and the like. 1

Although various systems and apparatus have heretofore been proposed for the same general purpose, all of same have been unsatisfactory or impractical for one or more of a number of reasons, including lack of flexibility for permitting both group practice and individual demonstration of operating techniques, extreme and unnecessary complexity resulting in high installation and maintenance costs, lack of realism in the adaptability thereof for close simulation in the instruction system of the device with respect to which instruction is to be given, the necessity for multiple cables or connections running between each student-operated assembly respectively and some central station, etc.

Accordingly, it is the primary object of this invention to provide an improved system and apparatus overcoming all of the above mentioned and other disadvantages of the systems and apparatus previously proposed for use under similar circumstances.

It isanother important object of this invention to pro-' vide such a system and apparatus including a single central stationand a plurality of substantially identical operating assemblies which may be coupled serially with each other and the central station, rather than requiring 7 operating assembly individually and the central station.

Another important object of the invention is to provide such a system and apparatus having means adapting the same for operation either in a condition by which the student at any individual operating assembly may control the action of the central station and a condition in which the students operating all of the individual assemblies must correctly operate their respective assemblies in order for the central station to be actuated.

Another important object of the invention is to provide such a system and apparatus which is simple in con: struction and operation and, accordingly, relatively inexpensive, whereby the invention is practical for use in schools and similar institutions which would not have available the funds for the purchase or maintenance of more complex equipment.

Another important object of the invention is to provide such a system and apparatus which is substantially foolproof or of nature not permitting any one or more .Fatented Mar; 8, 1960 lice students to effectively mislead the instructor with respect to their state of proficiency in performing the operations being taught. I

Still other important objects of the invention will be made clear or become apparent from the description of the illustrative, preferred embodiment thereof that follows.

In the accompanying drawings:

Figure l is a fragmentary schematic diagram of a system and apparatus made in accordance with the principles of the invention as same might be applied to the problem of group instruct-ion of students'in playing the piano, the central station portion of such system being shown as associated with the regular keyboardelements of a single, conventional piano for operating the latter;

Fig. 2 illustrates a possible modification of the indicating portion of the central station adapted for playing a piano directly by vibration causing impact with the strings of the piano; and

Fig. 3 illustrates -a further one of the many possible modifications of the indicating means of the central sta' tion, wherein the same is adapted for operating an electrical switch, which may be coupled with an audible sound generator, a light bulb or the like.

Referring now with particularity to Fig. 1, the apparatus to the left of the dotted line 10 in the drawing comprises the central station portion of the system, which is generally designated by the numeral 12. Such 'central station includes a source of electrical power 14, which might be either a battery or an alternating current power main; a plurality of indicating mechanisms respectively designated generally by the numerals 16, 18 and 20 (although it will be understood that there is provided a corresponding mechanism 16 et seq. for each shiftable key or element 22 included in the portion of the entire scale of a piano or the like with respect to which instruction is to be given).

As illustrated in Fig. l, the mechanisms 16 et seq. may each comprise an electromagnetic coil or solenoid 24 having a shiftable element 26 operably associated therewith and adapted for shifting against the yieldable bias of a spring or the like 28 to a position for engaging and operating the keyboard element 22 of the piano or the like with which the central station 12 is associated. For the sake of illustration, the three keys 22 of the piano illustrated in Fig. 1 might correspond for instance to the notes C, D and B respectively of the scale of such tivation of the coil 24.

In Fig.' 2, it will be seen that the element 26' associated with each electromagnetic coil 24 could be L- shaped and provided with suitable hammer structure 30 adapted for impactively engaging a corresponding actual string 32 of the piano to vibrate the same whenever the coil 24 is energized.

Similarly, Fig. 3 illustrates another possible type of indicating means'which could be used wherein the coil 24 is operably coupled with a relay switch generally designated 34 for controlling the operation of a sound generator 36 having a loud-speaker 38, or the switch 34 may be utilized to control the operation of a corresponding electric lamp or other electrically responsive structure as will be clearly understood by those skilled in the art.

In any event, one side of the power source will preferably be coupled by conductive means 40 and 41, 42, 43 et seq. with one side of each of the electricallyresponsive indicating mechanisms 16 et seq. The other side of the power source 14 is coupled by conductive means 44 with a terminal 46 on the central station $2,!

The side of each of the mechanisms 16 opposite to the power connections 41 et seq. are coupled to corresponding terminals 47, 48, 49 et seq. by conductive means 50, 51, 52 et seq.

Although any desired plurality of student-operable assemblies could be provided, there is shown for illustrative purposes in Fig. 1 three of such assemblies generally designated 106, 2th and 3%. An additional assembly generally designated 460, which may be substantially identical to the assemblies E60, 206 and 360, is provided for operation by the instructor.

Each of the assemblies Still], 2%, 300 and 400 includes a keyboard comprised of a plurality of keys represented schematically in the drawing and identified by the nu meral 54, which it will be understood are arranged and made to appear as nearly like the keys 22 of the'piano or other instrument with respect to which instruction is to be given as is possible. There is a key 54 at each of the assemblies 160, 260, 366 and 4% respectively for each of the keys 22 of the piano respectively or, in other words, for each of the indicating mechanisms 16 et seq. respectively.

Each key 54 is operably coupled with a pair of ganged, normally open, single pole, single throw switches 56 and 58, which are adapted to be closed whenever, but only when, the person operating the particular assembly 106, 200, 390 or 466 depresses the corresponding key 54 of the assembly keyboard in substantially the same manner that he would do it playing upon the keys 22 of the piano or other instrument in question.

Also associated with each of the keys 54 on each of the assemblies 166, etc. is a two-position switching apparatus 60 including a pair of ganged, single pole, single throw circuit breakers 62 and 64.

Each of the assemblies 163, etc. is provided with a power input terminal designated by the numeral 46 preceded by the one hundreds digit corresponding to the identification of the particular assembly and with a power output terminal similarly designated by the numeral 46' preceded by the appropriate one hundreds digit. The power terminal 46 of central station 12 is coupled with the input terminal 146 of the assembly 165) by conductive means 65, the output terminal 146 of assembly lllil is coupled with the input terminal 246 of assembly 260 by conductive means 65 and so forth with the power output terminal of each of the assemblies 1%, etc. directly coupled to the power input terminal of the next succeeding one of assemblies 106, etc. It may be noted that the assembly 460, which is normally operated by the instructor, preferably comprises the last of the assemblies 109, etc. in the series hooloup thereof, that is, the one most remote from the central station 12, regardless of how many assemblies 166, etc. are used. The power input and power output terminals 146 and 146, and the corresponding ones provided in each of the other asseme blies 200, etc. are directly coupled by conductive means 66.

Each of the mechanism control terminals 47, 48, 49 et seq. is directly coupled by conductive means 67, 68, 6? et seq. with a corresponding terminal 147, 148, 149 et seq. of the assembly 1%.

The connection of the various control output terminals 1 57, 148, 159 et seq. of assembly ltlt) (as well. as the corresponding control output terminals 247, 248, 249 et seq. for assembly 2%, 34-7, 343, 349 et seq. for assembly 390 and 447, 448, 249 et seq. for assembly 46%) are identical and bear the same relationships to the various circuit breakers 62 and. 6 and switch devices 6 and 58 associated with the corresponding key 54 of the assembly Kilt) and so on in question. Accordingly, the remaining electrical connections will be described only in such detail as is necessary for understanding the'diagram of Fig. l and, insuch connection, reference will be had particularly' to the connection of the circuit breakers 62 and tie, the switching devices 56 and 58, the control output lterminal 147 and the control input terminal 147' associated with the key 54 of assembly 1% corresponding to the indicating mechanism 16.

Thus, the control output terminal 147 is coupled by conductive means 79 with one side of the circuit breaker 64, the other side of which is coupled by conductive means 80 with the control input terminal 147. Switching device 56 is coupled in parallel with circuit breaker 64 by conductive means 81, 82 and 83. Switching device 58 is coupled in series with circuit breaker 62 by conductive means 84, the other side of switching device 58 being coupled with control input terminal 147' by conductive means 85, 32 and Si) while the other side of circuit breaker 62 is coupled with the power lead 66 by conductive means 86 and 87. As will be obvious from 1, these connections are the same for the structure associated with each of the keys 54 of all of the assemblies 169, etc. I

Each of the keys 54 of each of the assemblies 160, etc. has associated therewith a control input terminal designated by the numeral 47, 48, 49 et seq. preceded by the one hundreds digit corresponding to the particular assembly, the control input terminal l t? already having been mentioned. As will be apparent from the schematic diagram of Fig. 1 the control. output terminal 447 of assembly 400 is coupled with the control input terminal 347' of assembly 301) by conductive means 70, control output terminal 347 is coupled with control input terminal 247 by conductive means 71, the control output terminal 247 is coupled with control input terminal M7 by conductive means 72 and, as noted, the control output terminal 147 is coupled with the control terminal 47 of the central station 12 by conductive means 67. The coupling of the other control terminals is similar for each of the mechanisms 18, 20 et seq, the conductive means utilized being designated by the numerals '71), 7 1, 75 and 68, 76, 77, 78 and 69, etc.

Operation The keys 54 and related switching devices 56 and 58 and circuit breakers 62 and 64 associated with the mechaism 16 in each of the assemblies are shown in what may be designated their normal or standby condition. It will be noted that the circuit breakers 62 and 64 of all of the assemblies 100, etc. except those on the instructors assembly 400 are open, while such circuit breakers 62 and 64 of assembly 400 are normally always maintained in closed condition. All of the switching devices 56 and 58 of all of the assemblies 100, etc. are, still referring only to those associated with the mechanism 16, open as they would be when none of the keys 54 in question are depressed or operated. In this condition of the apparatus, the mechanism 16 remains deenergized and unactuated, since the potential energizing circuit for the coil '24 of mechanism 16 is broken by the open circuit breaker 64 and open parallel switch 56 associated therewith as a part of the first assembly 106.

The structure of the assemblies Mill, etc. corresponding to the indicating mechanism 18 are shown in that disposition they would have when the mechanism 18 is operated in one of the alternatively available modes of operation of the apparatus. This particular mode of operation contemplates the necessity of the persons oper ating each of the assemblies 100 all simultaneously depressing their own key 54 corresponding to the mechanism it; in order for the latter to be actuated. Such mode of operation is accomplished by leaving the circuit reakers 62 and 64 of all of the assemblies 100, etc., except the last assembly 400, open. With the circuit breakers 62 and 64 thus disposed, the depression of less than all of the keys 54 corresponding to the mechanism 18 will be ineffective to operate the mechanism 18. When all of the said keys 54 are operated to close the corresponding switches 56 and 58, an energizing circuit for the mechanism 18 may be traced from the power source 14 through terminal 46, conductor 65, terminal 146, conductor 66, terminal 146, conductor 65, terminal'246, conductor 66, terminal 246', conductor 65, terminal 346, conductor 66, terminal 346, conductor 65, terminal 446, conductor 66, conductor 37 of assembly 4%, closed circuit breaker 62 of assembly 40%}, conductor 84 of assembly 400, closed switch 53 of assembly 400, conductors 85 and 83 of assembly 406, closed switch 56 v of assembly 460, conductors 81 and 79 of assembly 46G,

terminal448, conductor 75, terminal 348, conductors $0, $2 and 83 of assembly 3%, closed switch 56 of assembly 300, conductors 81 and 79 of assembly 300, terminal 348, conductor '74, terminal 24%, thence through conductors 80, 82 and 83, closed switch 56 and conductors 81 and 79 all of assembly 209, terminal 248, conductors 75, terminal 148, thence through conductors 3t), 32 and 83, switch 56 and conductors 81 and 79 all of assembly 104 terminal 148, conductor 68, terminal 48 andconductor 51 to mechanism 13, which is oppositely connected with battery 14 through conductors 42 and 4G.

The other mode of operation of the apparatus of the invention contemplates that the operator of any one of the assemblies 100, etc. may activate a mechanism such as at 20 by depressing his key 54 corresponding thereto.

In this mode of operation the circuit breakers 62 and 64 of all of the assemblies are closed by proper shifting of the devices 60. In Fig. 1, the mechanism 20 is illustrated as being actuated by the operator of assembly 300 depressing his corresponding key 54 to close the switches 56 and 58 associated therewith. The pertinent energizing circuit for the mechanism 20 is traceable as above to the conductor 87 of assembly 300, thence through conductor 86, closed circuit breaker 62, conductor 84, closed switching device 58, conductors 85, 82 and 80, closed circuit breaker 64 and conductor 79 all of assembly 300 to control output terminal 349, through conductor 77 to control input terminal 249', thence through conductor 80, closed circuit breaker 64 and conductor 79 all of assembly 200 to control output terminal 249, through conductor 78 to control input terminal 149' thence through conductor 80, closed circuit breaker 64 and conductor 79 all of assembly 100 to control output terminal 149, then through conductor 69 to terminal 49 and through conductor 52 to the mechanism 20, which is oppositely connected with source 14 through conductors 43 and 40. It will be observed that an analogous circuit for energizing the mechanism 20 may be traced through the corresponding structure of any of the assemblies 100 when the corresponding key 54 thereof is depressed to close the switching devices 56 and 58 associated therewith.

It will be thus perceived that the system and apparatus contemplated by this invention offers the instructor a great deal of flexibility in utilizing the apparatus of the invention for furthering the instruction being given, whether the action desired from the system is, at the moment, group practice (as illustrated in conjunction with the mechanism 18) or individual demonstration (as illustrated in connection with the mechanism 20). Although different of the mechanisms 16 et seq. could be set up to activate responsive to different modes of operation of the apparatus by appropriate settings of the circuit breaking devices 60, it ispresumed that under ordinary circumstances all of the mechanisms 16 et seq. would be set to operate in the same fashion, that is, to respond to the same mode of operation of the system. The changeover is quickly and easily accomplished by manipulation of the circuit breaking devices 60 which could, if desired, be gauged for simultaneous operation as to all of the devices 60 on any one of the assemblies 100, etc.

It will now be apparent that the system and apparatus contemplated by this invention are ideally adapted for the accomplishment of allthe above mentioned and other objects thereof. it will be also perceived, however, that certain minor modifications and changes could be made from the exact arrangement described for illustrative purposes without departing from the true spirit or intention of the invention. Accordingly, it is to be understood that the invention shall be deemed limited only by the scope of the claims that follow.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

1. in apparatus for use in instructing a group of students in playing a keyboard instrument such as a piano having a plurality of manually shiftable keys, a corresponding plurality of sound emitting, string structures and means operably coupling each of the keys with a corresponding structure for activation of the latter when the corresponding key is shifted during playing, the combination of a plurality of keyboard simulating assemblies respectively adapted for operation by different ones of said group of students and each including an identical series of manually shiftable, key simulating members corresponding to the keys of at least a portion of said keyboard; a pair of ganged, normally open, single pole, single throw switches for each member respectively of each assembly respectively operably coupled with the corresponding member for closure thereby when the latter is shifted; a pair of ganged, manually operable, single pole, single throw circuit breakers for each member respectively of each assembly respectively; an electrically responsive mechanism for each member respectively of one of the identical series thereof, each mechanism being adapted, when operated, for effecting a sensible representation of the operation of a corresponding one of said structures; a source of electrical power having a pair of terminals; first electrical circuit means coupling one terminal with one side of each of the mechanisms; second electrical circuit means for each mechanism'respectively coupling one of each of said pair of circuit breakers corresponding therewith in series with said other, one end of each second circuit means being coupled with the other side of the corresponding mechanism; third electrical circuit means for each memberrespectively coupling one of said pair of switches corresponding therewith in parallel with the corresponding said one circuit breaker; fourth electrical circuit means for each member respectively coupling the corresponding other switch and other circuit breaker in series with each other; fifth electrical circuit means for each fourth circuit means respectively coupling the latter between the other terminal and that side of the corresponding said one circuit breaker remote from the corresponding mechanism.

2. In apparatus as set forth in .claim 1, wherein each mechanism includes shiftable parts adapted for disposition adjacent a corresponding one of said keys and for engaging the latter to shift the same for activating the corresponding structure when the mechanism is operated.

3. In apparatus as set forth in claim 1, wherein each mechanism includes shiftable parts adapted for disposition adjacent a corresponding one of said string structures and for striking the latter to activate the same when the mechanism is operated.

References Cited in the file of this patent UNITED STATES PATENTS Faulkner Oct. 29, 1957 

